Daystar's Remix of Rationality
by daystar721
Summary: Fan edit of the first few chapters of LessWrong's HPMOR to smooth out tone/characterization, and make it more accessible to those not familiar with Harry Potter canon.
1. Chapter 1

This is a fanfic of LessWrong's famous Harry Potter and the Methods of Rationality. I'm merely experimenting with a rewrite of the first few chapters to examine how they might be "smoothed out" to better match the rest of the story in tone and characterization, and adding more context so as not to assume the readers are familiar with the canon series. J.K. Rowling owns Harry Potter, and as far as I'm concerned, LessWrong owns Rational Harry.

Chapter 1: A Day of Fairly Low Probability

* * *

_Beneath the moonlight glints a tiny fragment of silver, a fraction of a line..._

_(black robes, falling)_

_...blood spills out in litres, and someone screams a word._

* * *

Harry James Potter-Evans-Verres was doing his best to ignore the yelling outside his cupboard.

It was an hour before supper, and he was lying in the cupboard under the stairs and reading a fantasy novel. Normally he enjoyed reading in companionable silence with his father in his study, or tuning out the sound of his mother's soap operas in the living room, but when he wanted quiet that even his room couldn't provide, he would go under the stairs. It was a private, cozy place, mostly insulated from the sounds of phone conversations, television, or outside traffic.

This particular night however, the walls were no match for the steadily rising voices of Michael and Petunia Evans-Verres, and soon Harry began to catch bits and pieces of the conversation.

"_...just rubbish... fourth time this week... a silly prank, Petunia-"_

Harry adjusted his glasses and tried to concentrate on the book. The author was attempting to explain, through an old wizard's limited grasp of biology and chemistry, how the dragons in his world breathed fire. Though Harry generally preferred science-fiction, he always enjoyed fantasy best when the writers at least _tried_ to put some of the magic in rational, understandable terms: it fired up his imagination to think outside the box for what was possible, if not terribly probable.

"_-not a prank, I told you... __have to __show him, or they'll keep__... more and more of them..."_

"_...__nonsense, there's no need... worry about crackpots sending him letters!"_

Unfortunately, now his imagination was preoccupied with what kinds of letters his dad was keeping from him. Harry closed his book, no longer able to concentrate as a familiar bitterness flared up in him.

It wasn't that his parents mistreated him. Far from it: he'd been sent to the best primary schools, and when that proved insufficient was given the best tutors an endless pool of starving uni students could provide. He'd always been encouraged to study whatever caught his attention, was bought all the books he wanted, was sponsored in whatever maths or science competitions he entered. He knew he was exceedingly lucky, and was always grateful for what his parents gave him... but he would have been satisfied with half as much if it meant he had their respect.

Of course if asked, his parents would say they respected him. An Oxford Professor of Biochemistry and his liberal wife were _expected _to show an enlightened view of child-rearing that included respect. But that respect meant something different than it would for a fellow adult, who they would never have dreamed of talking about as if he weren't in the house, let alone making decisions for him.

It wasn't their fault: society as a whole had such low expectations of children. And if it was ever going to change, it would be up to those like him to change it.

So Harry swung his legs out of the small hammock he'd strung to the walls, turned off the lantern his father had hung up for him, and opened the door into the hallway.

The voices immediately quieted. By the time he stepped into the living room his parents were sitting calmly on the couch, watching the news on a television that stuck out from its surroundings. The Evans-Verres living room was dominated by books. Every inch of wall space was covered by a bookcase going almost to the ceiling. Some bookshelves were stacked to the brim with hardback books: science, maths, history, and everything else. Other shelves had two layers of paperback science fiction, one set right side up, the other stacked sideways in what's left of the space above. And it still wasn't enough. Books were overflowing onto the tables and the sofas, covered the top of the television, and made little stacks under the windows.

"Hi Mum, Dad. Is everything alright?"

"Hello Harry." His mother turned to him with a warm smile, face still young and pretty despite her age. "Yes, everything's fine."

"Did we disturb your reading son?" his father said, looking contrite. "We're sorry, our debate got a bit passionate at the end there." Michael chuckled.

Harry and his mother exchanged knowing smiles. Professor Evans-Verres viewed arguments as uncivilized, and so any he participated in were automatically elevated in status to "debate." "It's alright. I just couldn't help but overhear," Harry said with mild emphasis, "and it sounded like a letter arrived for me?"

He saw it in the quick glance they gave each other, his mother's expectant, his father's calculating. Harry knew his father was struggling with some mighty cognitive dissonance. One part of him felt guilt from withholding someone's mail from them, a grievous breach of privacy. The other part felt entitled by societal norms that parents were allowed to decide for their children what information they should or shouldn't have, no matter how bright and precocious those children might be.

"Yes," Petunia said after the silence stretched on a few seconds. "It's the first time I've seen it, or I would have told you sooner. Your father thinks it's just prank mail, but he doesn't understand-"

"Well no harm in having a look then, right?" Harry said, and held his hand out expectantly, brow raised in an expression of innocent patience. He wasn't quite sure what he'd do if his father refused, trying to reason with him rarely worked on any topic that concerned Harry's subordinate status...

After a moment though his father nodded and stood up, walking toward the trash and fishing an envelope and a couple papers from it. "Quite right Harry, no harm in looking. You're a bright boy, and I know you won't get suckered in by whatever crock they're selling."

Michael handed the letters and envelope to Harry, who had to choke back a retort to the patronizing tone his father had adopted now that he was giving in. Admitting one's mistakes was for scientific journals, apparently: not for adults to do to children...

Harry chided himself on such bitter thoughts as he went to the table. He knew this was a sore spot for him, and it occasionally took awhile for his temper to calm down. So he forced himself to smile back at his dad, then straightened the first thick, rich paper out and began to read, acutely aware of his parents' stares.

Harry's eyes scanned the letter in a few seconds, blinked, then looked up to meet theirs.

"What."

Michael Evans-Verres smiled. "Yes, rather silly I th-"

Harry held his hand up, then looked back down at the parchment (that's what you'd call material like this, Hary knew, simple "paper" didn't suffice) and slowly reread the message.

_Dear Mr. Potter,_

_We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment._

_Term begins on 1 September. We await your owl by no later than 31 July._

_Yours sincerely,_

_Minerva McGonagall_

_Deputy Headmistress_

On the second sheet he found a list that wouldn't be out of place in a fantasy RPG book.

"What is it, some kind of summer camp?" Harry asked as he eyed the impressive seal heading the parchment: a lion, snake, raven and badger surrounding an ornate H. He smiled as he looked back at the name of the school. _Heh. "Hogwarts." W__hat, was "Newteyes" taken?_

"No, Harry," his mother said. "It's not a summer camp. As I was telling your father..." She took a deep breath, straightened in her seat, and avoided looking at her husband, gaze steady on Harry. "My sister... your mother, Lily... was a witch. She got that same letter. I'd promised to keep it secret, my whole family did, but now it's clear you're meant to know, if they've come for you like they did her."

Harry exchanged a glance with his father, feeling a mix of exasperation and confusion. Mum rarely spoke of his biological parents. It wasn't taboo or anything, it just never really came up. They'd died in a car crash when he was one year old, the same crash which had given him the lightning shaped scar on his forehead. To hear that they were Wiccan wasn't terribly surprising considering some of Petunia's beliefs, but the gravity of her tone didn't match the subject matter.

"Well that's, er, very interesting. I guess. But what does her religion have to do with me? Who's 'they?'" He didn't particularly like the ominous sound of them "coming for him," whoever they were. He imagined a shadowy coven meeting in a forest and pronouncing it time to bring the young Potter into the fold.

"It wasn't a religion. I'm saying she was an _actual_ witch. She could do magic. Her husband, your father, was a wizard. They both went to this magic school, Hogwarts, when they were eleven. And that you got that letter, it means you're a wizard too, Harry."

Michael Evans-Verres laughed, and Harry almost joined him. Petunia Evans-Verres had always been something of the odd-woman-out in their family. Some of the most "spirited debates" he could remember between his parents involved her superstitions, and he had a clear memory as a child of her waving a crystal of some kind in careful patterns over him when he was sick.

When he was younger he used to enjoy going with her to the smoky, mysterious shops she would occasionally frequent, with their pungent odors and exotic wares. Thankfully his father's books had taught him how to critically examine the beliefs sold in such places, and a few years ago he had begun to find their air of obscure mysticism groundless and mildly irritating.

Harry smiled down at the parchment listing the "school supplies." Wand, spell books, potion ingredients... he quickly scanned the latter. Nope, no "hog warts" listed, though newt eyes did indeed show up, as well as powdered hens' teeth. He wondered how expensive that would be: he knew there was some research being done on atavism in chickens that resulted in them growing vestigial teeth, and that the mutation was rather rare. Aboriginal shaman and medicine men must have found plenty of uses for it, or imagined them at any rate. He wondered what Hogwarts pretended to use them for. Good dental hygiene?

And yet he didn't laugh with his father. Because...

Because somewhere in him was a strange certainty that she was right, in this, the most unlikely of cases. _You're a wizard too, Harry._

"Well, maybe someday he'll be a wizard at chess," his father said, still smiling as he turned back to the news. "But if whoever keeps sending those letters shows up at the door in a robe and pointy hat, I'm calling the men in the white coats."

Petunia continued to look only at Harry, her gaze intent, waiting.

"Mum," he said. "What do you mean by 'wizard?'"

Petunia bit her lip. "I can't just tell you. You'll think I'm-" She swallowed, and Harry felt confused. His mother had always defended her less rational beliefs with an exasperating calm, merely shrugging off logical arguments and relying on some inner conviction. This sudden nervousness, and the confusion he felt from it, made him pay attention. "Listen. I wasn't - always like this -" She gestured at herself, as though to indicate her lithe form. "Lily did this. Because I... I _begged_ her. For years, I begged her. Lily had always been prettier than me, and I'd... been mean to her, because of that, and then she got _magic,_ can you imagine how I felt? And I _begged_ her to use some of that magic on me so that I could be pretty too, even if I couldn't have her magic, at least I could be pretty."

Harry watched in alarm as tears gathered in Petunia's eyes.

"And Lily would tell me no, and make up the most ridiculous excuses, like the world would end if she were nice to her sister, or a centaur told her not to - the most ridiculous things, and I hated her for it. And when I had just graduated from university, I was going out with this boy, Vernon Dursley, he was fat and he was the only boy who would talk to me. And he said he wanted children, and that his first son would be named Dudley. And I thought to myself, _what kind of parent names their child Dudley Dursley?_ It was like I saw my whole future life stretching out in front of me, and I couldn't stand it. And I wrote to my sister and told her that if she didn't help me I'd rather just -"

Petunia stopped. Harry felt somewhat wretched for being responsible for her having to relate such an obviously painful memory. A glance at his father showed his dad similarly stricken. He'd never known that Mum had been through such a dark period, had been so envious of her sister... he wondered how much guilt she must have felt after his biological parents had died.

"Anyway," Petunia said, her voice small, "she gave in. She warned me it was dangerous, and I said I didn't care. I drank this potion and I was sick for weeks, but when I got better my skin cleared up and I finally filled out and... I was beautiful. People were _nice_ to me," her voice broke, "and after that I couldn't hate my sister any more, especially when I learned what her magic brought her in the end -"

"Darling," Michael said gently, "you got sick, you gained some weight while resting in bed, and your skin cleared up on its own. Or being sick made you change your diet-"

"No, it was nothing like that," Petunia said. "It was magic, real magic. I saw it, other things-"

"Petunia," Michael said. The annoyance was creeping back into his voice. "You _know_ that can't be true. Do I really have to explain why?"

Petunia wrung her hands. She seemed to be on the verge of tears. "My love, I know I can't win arguments with you, but please, you have to trust me on this -"

"_Dad! Mum!_ "

The two of them stopped and looked at Harry. He took a deep breath and thought about the problem. "Mum, _your_ parents didn't have magic, did they?"

"No," Petunia said. "Just Lily."

"Then your family also must not have believed her letter. How did _they_ get convinced?"

"Ah..." Petunia said. "They didn't just send a letter. They sent a professor from Hogwarts. He -" Petunia's eyes flicked to Michael. "He showed us some magic."

"Well there we are then. You don't have to fight over this," Harry said firmly. "If it's true, we can just get a Hogwarts professor here and see the magic for ourselves, and Dad will admit that it's true. And if not, then Mum will admit that it's false. That's what the experimental method is for, so that we don't have to resolve things just by arguing." Hoping against hope that this time, just this once, they would listen to him...

"Oh, come now, Harry," Professor Evans-Verres said. "Really, _magic?_ I thought you'd know better than to take this seriously, even if you're only ten."

_I. Shall. SCREAM_.

"Mum," Harry said instead, keeping his voice calm. "If you want to win this argument with Dad, look in chapter two of the first book of the Feynman Lectures on Physics. There's a quote there about how philosophers say a great deal about what science absolutely requires, and it's all wrong, because the only rule in science is that the final arbiter is observation - that you just have to look at the world and report what you see. Um... off the top of my head I can't think of where to find something about how it's an ideal of science to settle things by experiment instead of arguments -"

His mother looked at him and smiled. "Thank you, Harry. But," she looked back at her husband. "I don't want to win an argument with your father. I want my husband to just... listen to his wife who loves him, and trust her just this once..."

Harry closed his eyes briefly. _Hopeless._ Both of his parents were hopeless.

Now they were getting into one of _those_ arguments again, one where his mother tried to make her husband feel guilty, and his father tried to make his wife feel stupid.

"I'm going to go to my room," Harry announced. His voice trembled a little. "Please try not to fight too much about this, Mum, Dad, we'll know soon enough how it comes out, right?"

"Of course, Harry," said his father, and his mother gave him a reassuring kiss, and then they went on "debating" while Harry climbed the stairs to his bedroom.

He shut the door behind him and tried to think, wandering past his own bookshelves crammed with textbooks and sci-fi to lie on his bed.

The funny thing was, he _should_ have agreed with Dad. No one had ever seen any evidence of magic, and according to Mum, there was a whole magical world out there. How could anyone keep something like that a secret in a world of video cameras and spy satellites? More magic? That seemed like a rather suspicious sort of excuse.

Except that some part of Harry was utterly convinced that what his Mum said was true. He was magic... a wizard.

Was it simple ego? What child didn't want to believe they possessed hidden, magic powers? He knew he had an inflated sense of self-importance as others judged it. He'd always vowed to one day justify it by proving himself unique. Of course, he'd figured it would be somewhere in the realm of science. He'd imagined becoming a world renowned biologist, curing cancer and extending lifespans indefinitely. Or going into physics to perfect cold fusion, ending the planet's energy needs and propelling humanity to the stars. Reasonable things. Mostly. Not magic, at any rate.

Maybe his powers of reason had been impaired somehow. He frowned, probing his skull with his fingers as if some wound would present itself. He hadn't hit his head on anything lately... not that he could remember in any case. _Would_ he even remember? There was a scary thought. Harry mentally jumped through some quick mental hoops to confirm that yes, the least complicated answer that fit all the facts is most likely to be the true one, that all claims require evidence and that extraordinary claims require extraordinary evidence, that two plus two still equaled four.

It should have been a clean case for Mum joking, lying or being insane, in ascending order of awfulness. If Mum had sent the letter herself, that would explain how it arrived at the letterbox without a stamp. A little insanity was far, far less improbable than the universe really working like the contents of that letter implied.

What about his mother's other views? Was he any more susceptible to those? He considered her belief that atoms arranged in a particular pattern identified as a "crystal" could somehow destroy bacteria or viruses in his body when touched to his skin... specifically those bacteria or viruses deemed "harmful," opposed to all the beneficial ones... Yes, that he could still rationally reject as a form of wish fulfillment without any evidence to back it up. If the person from Hogwarts came to their house and started bending spoons, he would toss the letter in the trash and think nothing further of it.

But that _he_ was magical... that irrational belief still stayed. And he could think of no evidence to account for it: no moments in his life when he'd exhibited supernatural or unexplainable powers, no hidden talent manifesting in times of great peril or passion. But he still believed he was magic.

Harry rubbed his forehead, grimacing. _Don't believe everything you think,_ Harry reminded himself. _So_ _where do you come from, strange little prediction?_ _Why do I believe what I believe?_

Usually Harry was pretty good at answering that question, but in this particular case, he had no _clue_ what his brain was thinking. Was this what "faith" felt like? He couldn't remember having a belief based on faith, except when he was very young. Some people, unfamiliar with the scientific method or rationalism, seemed to think that science took faith, since no one did every experiment themselves, but rather relied on other scientists or textbooks to tell them what was true or not true.

The problem with this view was that no scientist had "faith" in textbooks, other scientists, or even the scientific method. They had _confidence_ in them. Somewhere, someone was able to do the experiments, verified the results through repeated tests, and then subjected their findings to peer review. And if he wanted, Harry could take the time and effort to learn the information and repeat the experiment himself. Belief in science relied on the _external,_ not the internal, and thus could be shown to others, taught and learned. He no more had faith in science than he had faith that Dad's car would start tomorrow: he had confidence based on experimentation and observation.

This new belief, however, was not based on external factors. He couldn't describe it to anyone in a way that would make sense. He couldn't demonstrate the belief and have it peer reviewed. It just was.

Harry mentally shrugged. A button calls to be pushed, a handle yearns to be turned, and the thing to do with a testable hypothesis is to go and test it.

He went to his desk, shoved some of the books to the side, and took a piece of lined paper from a drawer to start writing.

_Dear Minerva McGonagall  
_

Harry paused, reflecting, then discarded the paper for another, tapping another millimetre of graphite from his mechanical pencil. This called for careful calligraphy.

_Dear Deputy Headmistress Minerva McGonagall,_

_Or Whomsoever It May Concern:_

_I recently received your letter of acceptance to Hogwarts, addressed to Mr. H. Potter. You may not be aware that my genetic parents, James Potter and Lily Potter (formerly Lily Evans) are dead. I was adopted by Lily's sister, Petunia Evans-Verres, and her husband, Michael Verres-Evans._

_I am extremely interested in attending Hogwarts, conditional on such a place actually existing. Only my mother Petunia says she knows about magic, and she can't use it herself. My father is highly skeptical. I myself am uncertain. I also don't know where to obtain any of the books or equipment listed in your acceptance letter._

_Mother mentioned that you sent a Hogwarts representative to Lily Potter (then Lily Evans) in order to demonstrate to her family that magic was real, and, I presume, help Lily obtain her school materials. If you could do this for my own family it would be extremely helpful._

_Sincerely,_

_Harry James Potter-Evans-Verres._

Harry added their current address, then folded up the letter and put it in an envelope, which he addressed to Hogwarts. Further consideration led him to obtain a candle and drip wax onto the flap of the envelope, into which, using a penknife's tip, he impressed the initials H.J.P.E.V. If he was going to descend into this madness, he was going to do it with style.

Then he opened his door and went back downstairs. His father was sitting in the living-room and reading a book of higher maths to show how smart he was, and his mother was in the kitchen preparing one of his father's favourite meals to show how loving she was. It didn't look like they were talking to one another at all. As scary as arguments could be, _not_ arguing was somehow much worse.

"Mum," Harry said into the unnerving silence, "I'm going to test the hypothesis. According to your theory, how do I send a letter to Hogwarts?"

His mother turned from the sink to look at him uncertainly. "I don't know, I think you have to own a magic owl."

That should've sounded highly suspicious, _oh, so there's no way to test your theory then,_ but the peculiar certainty in Harry seemed willing to stick its neck out even further.

"Well, the letter got here somehow," Harry said, "so I'll just wave it around outside and call 'letter for Hogwarts!' and see if an owl picks it up. Dad, do you want to come and watch?"

His father shook his head minutely and kept on reading. _Of course,_ Harry thought to himself. Magic was a disgraceful thing that only stupid people believed in; if his father went so far as to _test_ the hypothesis, or even _watch_ it being tested, that would feel like _associating_ himself with that...

Only as Harry stumped out the back door into the garden did it occur to him that if an owl _did_ come down and snatch the letter, he was going to have some trouble telling Dad about it.

_But - well - that can't_ really _happen, can it? No matter what my brain seems to believe. If an owl really comes down and grabs this envelope, I'm going to have worries a lot more important than what Dad thinks._

Harry took a deep breath, and raised the envelope into the air.

He swallowed.

Calling out _Letter for Hogwarts!_ while holding an envelope high in the air in the middle of your own back garden was... actually pretty embarrassing, now that he thought about it.

_No. I'm better than this. I will use the scientific method even if the result makes me feel stupid._

"Letter-" Harry said, but it actually came out as more of a whispered croak.

Harry steeled his will, and shouted into the empty sky, "_Letter for Hogwarts! Can I get an owl?_ "

"Harry?" asked a bemused woman's voice from nearby.

Harry yanked down his hand as if it had caught fire, hiding the envelope behind his back like it was drug money. His whole face was hot with shame.

An old woman's face peered out from above the neighbouring fence, grizzled grey hair escaping from her hairnet. Mrs. Figg, the occasional babysitter. "What are you doing, Harry?"

"Nothing," Harry said in a strangled voice. "Hi Mrs. Figg. I'm just... testing a really silly theory-"

"Did you get your acceptance letter from Hogwarts?"

Harry froze_._

"Yes," Harry's lips said a little while later. "I got a letter from Hogwarts. They say they want my owl by the 31st of July, but-"

"But you don't _have_ an owl. Poor dear! I can't imagine _what_ someone must have been thinking, sending you just the standard letter."

A wrinkled arm stretched out over the fence, and opened an expectant hand. Hardly thinking himself at this point, Harry gave over his envelope.

"Just leave it to me, dear," said Mrs. Figg, "and in a jiffy or two I'll have someone over."

And her face disappeared from over the fence.

There was a long silence in the garden.

Then a boy's voice said, calmly and quietly, "What."


	2. Chapter 2

_Chapter 2: Everything I Believe Is False _

* * *

_"Of course it was my fault. There's no one else here who could be responsible for anything."_

* * *

Oddly enough, it might have been easier explaining to his dad that an owl had grabbed the letter after all.

"What? _Mrs. Figg_?" Professor Evans-Verres's shock was spectacular. Harry empathized completely. He sat at the table between the living room and kitchen, somewhat in a daze.

"Did she say what time they would be coming?" Petunia asked. She checked the pot roast and ran her hands over her hair, as if expecting someone to ring the doorbell any minute.

"We've known Mrs. Figg for ten years," Harry's dad said. "She's a perfectly reasonable woman, why on earth would she-"

"No Mum, she just said they'd be here in a 'jiffy or two.' I don't know how far they're coming, but it's probably not going to be..." Harry tralied off as he realized that, given the hypothesis being tested, it might well be before the pot roast was done. He tried to remind himself that was silly, teleportation would break so many laws of physics there might as well not _be_ any, but ever since he'd heard the word "Hogwarts" come out of Mrs. Figg's mouth, his brain didn't seem to be working properly. A part of his mind took note of his dad's comment about knowing Mrs. Figg for ten years. Had she moved here the year Harry had been adopted? That seemed significant, if he could only wrestle his mind into considering how.

"Maybe she sent the letters," Dad said. He began to to pace the limited floorspace of the living room, feet stepping around books with the unconscious ease of memory. "Or she's part of the same cult your sister was in-"

"Well better set an extra place just incase." Mum put a stack of plates in front of Harry, and he set the table for four, placing each fork and knife with an inordinate amount of attention. Dad's theories made sense of course, more sense than his did, but his strange certainty continued to color all his thoughts as he set out the cups.

Dad suddenly gripped the back of the couch, face horrified. "We let her _babysit_ you!"

A knock at the door froze them all in place.

Dad was the first to thaw. He straightened, squared his shoulders, and walked to the front door, dignity fully reinforced by his casual tweed homewear.  
Mum wiped her hands on a towel and followed, and Harry rushed after them, wondering if it would be Mrs. Figg and knowing somehow that it wasn't. Dad peered through the peephole and recoiled as if stung. Harry's anticipation redoubled.

"Yes, who's there?" Professor Evans-Verres's voice did not tremble.

"Professor Minerva McGonagall," said a formal, Scottish voice, and Michael twitched. Harry wondered why, until his dad opened the door.

Professor McGonagall was an older woman, perhaps in her sixties, with greying hair in a severe bun and square spectacles perched on her nose. She looked every inch the professor she claimed to be, but for two things: she wore a black robe of some rich fabric, and her hat was decidedly pointy.

Harry grinned. His father's mental image of "professor" had just been severely abused.

"Come in, please," Petunia said with a smile. "Supper's almost ready, if you're hungry."

"I ate, thank you." Professor McGonagall said, and walked inside. Harry and his parents stepped back to let her through.

"I'm Petunia Evans-Verres, so nice to meet you..." The two walked down the hall, leaving Harry and his dad by the door. Harry closed it, then exchanged a look with his father.

"What do you reckon?" he whispered. "Time to call the white coats?"

Dad snorted and clapped him on the shoulder with a grin. "Come on, let's get this foolishness done with." They followed the women into the living room.

"Got an experiment in mind?" Harry asked. He was still feeling off balance. That strange certainty was stronger now, as if this were all a formality, and he already accepted that the woman in their house was a witch, without quite being able to grasp what that would mean in a practical sense.

"I can't imagine anything I would come up with that she wouldn't make an excuse for," his father said, still keeping his voice low. Harry nodded, and decided to be forthright with their guest, who stood expectantly in the living room. She eyed the multitude of books with what looked to be an admiring air, which Harry found reassuring.

"Good evening Professor McGonagall. As I'm sure you're aware-" Harry stopped. He actually wasn't sure _what_ she was aware of. Had she received his letter? What had Mrs. Figg done, read it to her over the phone? Perhaps she had stopped next door to retrieve it before coming here... Harry stifled his questions and began again. "I'm Harry Potter-Evans-Verres. We were surprised by your letter, and have some doubts about its validity. Mum says she's seen magic before, but neither Dad nor myself have. If you could demonstrate the quality of your magic to us, that would be a good first step."

Professor McGonagall was watching Harry with an amused expression as he spoke. "Of course, I would be happy to." She pulled a thin wooden stick out of her sleeve with practiced grace, and Harry blinked. He hadn't seen the shape of it against the material, and it should have fallen out if it wasn't held there somehow. "Is there something specific that would persuade you?"

Still preoccupied with her sleight of hand, it took Harry a second to realize she was holding a "magic wand," and he said the first thing that popped into his head: "Can you shoot fire out of that?"

"Harry!" Mum said with some alarm, and Professor McGonagall's lips twitched in a brief smile.

"I could, but I think that would be dangerous." She glanced pointedly at their surroundings. "How about something less destructive?"

"Of course," Harry said, cheeks red. "Er... did you fly here? I didn't hear a car, and unless you live nearby I can't imagine how else you got here so quickly. If you could just... hover a bit? That might help. Wait, on second thought, levitate Dad."

Professor Evans-Verres gave Harry an approving nod, and stepped forward to face their guest with his arms crossed. Professor McGonagall lifted her wand, and Harry realized his mistake. "Wait!" he said. She lowered her wand, raising an eyebrow. "I want to make sure we do this right." He thought about it for a second while everyone watched him.

"Now, just to be clear," Harry said to his Dad. "If the professor does levitate you, when you know you haven't been attached to any wires, that's going to be sufficient evidence. You're not going to turn around and say that it's a magician's trick. That wouldn't be fair play. If you feel that way, you should say so now, and we can ask her to do something else instead."

Dad nodded, smiling good-naturedly. "Agreed."

"And you, Mum, your theory says that the professor should be able to do this, and if that doesn't happen, you'll admit you're mistaken. Nothing about how magic doesn't work when people are sceptical of it, or anything like that."

Mum glanced at Professor McGonagall's wand and nodded.

"Is that sufficient, Mr. Potter?" Professor McGonagall said. "Shall I go ahead and demonstrate?"

"Sufficient? Probably not, but it should do for now," Harry said. Once he saw her methodology he could better decide how to isolate her actions and their relation to the result... assuming there was a result. Did he really expect his father to start floating? "Proceed, please."

"Is there anything you'd like me to do?" Professor Evans-Verres said, still smiling. "Think light thoughts, perhaps?"

"No need, thank you," Professor McGonagall replied, and then, "_Wingardium Leviosa_."

Harry looked up at his father. "Huh."

His father looked down at him. "Huh."

There was a silent pause that Harry knew he would always remember... the moment when his world utterly changed. Everything was still, as if suspended in crystal: he and his mother, staring in shock, the witch holding her wand pointed up at his father, who hung a respectable three feet off the ground in complete defiance of gravity.

And then Professor Verres-Evans looked back at Professor McGonagall and said in a voice Harry had never heard him use, "All right, you can put me down now, thank you." His father was lowered carefully to the ground, and the moment was ended. The universe continued on as it had before.

Harry ruffled a hand through his dark hair. Maybe it was just that strange part of him which had _already_ been convinced, but... "That's a bit of an anticlimax," Harry said. "You'd think there'd be some kind of more dramatic mental event associated with updating on an observation of infinitesimal probability-" Harry stopped himself. Mum and the witch were looking at him oddly. Dad slowly sat down, not even bothering to move the book from the chair as he stared at the piece of wood in Professor McGonagall's hand. "I mean, with finding out that everything I believe is false."

Seriously, it should have been more dramatic. His brain ought to have been flushing its entire current stock of hypotheses about the universe, none of which allowed this to happen. But instead it just seemed to be going, _All right, I saw the Hogwarts Professor wave her wand and make __Dad__ rise into the air, now what?_

The witch was smiling benevolently upon them, looking quite amused. "Would you like a further demonstration, Mr. Potter?"

"You don't have to," Harry said. "Though I should probably ask you to do it again just to ensure experimental reliability, we've performed a definitive experiment. That wasn't some trick with mirrors, it wasn't hypnotic suggestion, he actually lifted off the ground, we all saw it... but..." Harry hesitated. He couldn't help himself. Actually, under the circumstances, he _shouldn't_ be helping himself. It was right and proper to be curious. "What else _can_ you do?"

"Besides shoot fire, you mean?"

Dad looked as alarmed as Mum had a moment ago.

"Yes, besides that." Though Harry actually would love to see it. He was starting to get excited. Would he really be able to fly? Conjure fire at will? How? Did he accelerate the atoms in the air until they combusted? _Maybe I use my body heat to-_

Professor McGonagall turned into a cat.

Harry scrambled back without thinking, backpedalling so fast that he tripped over a stray stack of books and landed hard on his bottom_._ His hands came down to catch himself too late, and there was a warning twinge in his shoulder as the weight came down unbraced.

At once the small tabby cat morphed back up into a robed woman. "I'm sorry, Mr. Potter," said the witch, sounding sincere, though the corners of her lips were twitching upwards. "I should have warned you."

Harry was breathing in short gasps. It felt like a dam had broken in his mind. His voice came out choked. _"You can't DO that!"_

"It's only a Transfiguration," said Professor McGonagall. "An Animagus transformation, to be exact."

"You turned into a cat! A _SMALL_ cat! You violated Conservation of Energy! That's not just an arbitrary rule, it's implied by the form of the quantum Hamiltonian! Rejecting it destroys unitarity and then you get FTL signalling! And cats are _COMPLICATED!_ A human mind can't just visualise a whole cat's anatomy and, and all the cat biochemistry, and what about the _neurology?_ How can you go on _thinking_ using a cat-sized brain?"

Professor McGonagall's lips were twitching harder now. "Magic."

"Magic _isn't enough_ to do that! You'd have to be a god!"

Professor McGonagall blinked. "That's the first time I've ever been called _that._"

A blur was coming over Harry's vision as his brain started to comprehend what had just occurred. Here was the shock he'd been expecting, all the stronger for its delay.

The whole idea of a unified universe with mathematically regular laws, that was what had been flushed down the toilet; the whole notion of _physics_. Three thousand years of resolving big complicated things into smaller pieces, discovering that the music of the planets was the same tune as a falling apple, finding that the true laws were perfectly universal and had no exceptions anywhere and took the form of simple maths governing the smallest parts, _not to mention_ that the mind was the brain and the brain was made of neurons, a brain was what a person _was_ -

And then a woman turned into a cat, so much for all that.

Harry's head hurt.

A hundred questions fought for priority over his lips, and the winner poured out: "And what kind of incantation is _Wingardium Leviosa?_ Who invents the words to these spells, nursery schoolers?"

"That will do, Mr. Potter," Professor McGonagall said crisply, though her eyes shone with suppressed amusement. "If you wish to learn about magic, I suggest that we finalise the paperwork so that you can go to Hogwarts."

"Right," Harry said in a daze. Paperwork. Some things never changed, it seemed, even in a world of magic. He pulled his thoughts together and stood up. The March of Reason would just have to start over, that was all; they still had the experimental method and that was the important thing.

"Are you alright darling?" Mum said, putting a hand on her husband's shoulder.

Professor Evans-Verres did look rather pale. He patted her hand. "I - I think so dear, thank you." He then brought her hand to his lips in a rare show of public affection. "And... I'm sorry."

Petunia smiled and squeezed his hand. "That's alright. I was just as doubtful with Lily, and I didn't have half as many good reasons to be as you."

Dad smiled at her, then looked at Harry. "I'm sorry to you too, son. You were right. 'The final arbiter is observation,' indeed. I don't know if I can quite take all this in properly, but..."

Harry had choked up a bit, and now smiled back at his parents. "I had some help, or I would probably have been just as doubtful. Maybe it's a wizard thing. I'll explain another time." He turned to Professor McGonagall, who he now remembered was also the Deputy Headmistress to Hogwarts. A real school for wizards and witches. He couldn't begin to imagine what it would be like, with professors like this. "I'm ready. How do I get to Hogwarts?"

A brief laugh escaped Professor McGonagall, as if extracted from her by tweezers. "I won't be whisking you away by magic, if that's what you're expecting. As the letter said, term starts September 1st. I will come again and explain how transportation will occur, as well as help you obtain your school supplies."

"Hold on a moment, Harry," his father said. "Remember why you haven't been going to school up until now? What about your condition?"

Professor McGonagall turned to face Michael. "His condition? What's this?"

"I don't sleep right," Harry said. He waved his hands helplessly. "My sleep cycle is twenty-six hours long. I always go to sleep two hours later, every day. 10PM, 12AM, 2AM, 4AM, until it goes around the clock. Even if I try to wake up early, it makes no difference and I'm a wreck that whole day. That's why I haven't been going to a normal school up until now."

"One of the reasons," said his mother. Harry winced. He didn't want his potential future teacher and Deputy Headmistress to have a biased opinion of him.

_Even if it might be a bit deserved?_ asked his inner self-critic.

_It could be important for the teachers to know,_ commented his utilitarian side. _Remember when our science project-_

_Shut up or they might not teach us magic! _said his Id, and the other parts of Harry promptly fell into agreed silence.

McGonagall gave a long _hmmmmm._ "I can't recall hearing about such a condition before..." she said slowly. "I'll check with Madam Pomfrey to see if she knows any remedies." Then her face brightened. "No, I'm sure this won't be a problem - I'll find a solution in time. Now," and her gaze sharpened again, "what are these _other_ reasons?"

Harry sent his parents a glare, then straightened his shoulders. "I," he said with deliberate gravity, "am a conscientious objector to child conscription. On grounds that I should not have to suffer for a disintegrating school system's failure to provide teachers or study materials of even minimally adequate quality."

Both of Harry's parents burst out laughing. "Oh," said Harry's father, eyes bright, "is _that_ why you bit a maths teacher in third year?"

"_She didn't know what a logarithm was!_"

"Of course," seconded Mum. "And biting her was a very mature response."

Dad nodded. "A well-considered policy to address the failings of a disintegrating school system."

"I was _seven years old!_ How long are you going to keep on bringing that up?"

"I know," said his mother sympathetically. "You bite _one_ maths teacher and they never let you forget it, do they?"

Harry turned to Professor McGonagall as his father chuckled. "Are you sure you can't just whisk me away now?"

"Quite sure." Professor McGonagall's restrained smile threatened to burst into a grin at any moment. "And there is to be no biting of teachers at Hogwarts, is that quite clear, Mr. Potter?"

Harry scowled at her. "Fine, I won't bite anyone who doesn't bite me first."

"Better not ask him to build a volcano either," Dad suggested, and his mother began howling with laughter. "Not unless you can make yourself magically fireproof."

"_Dad!" _Harry yelled, cheeks burning.

"Well," Professor McGonagall said. "I think, under the circumstances, that I should avoid taking you to purchase your study materials until a day or two before school begins."

"What? Why? The other children already know magic, don't they? I have to start catching up right away! I promise not to burn down the school!" It occurred to him exactly a second after saying it out loud that his _having_ to say it was not particularly encouraging.

"Rest assured, Mr. Potter," replied Professor McGonagall, "Everyone at Hogwarts will begin with the basics, and the school is quite capable of teaching its students without risk of self-destruction. On the other hand, I suspect that if I leave you alone for two months with your schoolbooks, even without a wand, I will return to this house only to find a crater billowing purple smoke, a depopulated city surrounding it and a plague of flaming zebras terrorising what remains of Oxford."

Harry's mother and father nodded in perfect unison.

"_Mum! Dad!_ "


	3. Chapter 3

Chapter 3: Comparing Reality To Its Alternatives

* * *

_"But then the question is - who?"_

* * *

"Now remember Harry, you're not under any obligation to be here."

"I know Mum."

"If you want to come home, just give me a call and I'll pick you right up."

"Yes Mum." _As if I'd turn back now._

Petunia Evans-Verres looked at Harry in the rear-view mirror of the car as if she could easily guess his thoughts, and seemed troubled by them. He'd spent the past few weeks in a mild frenzy, first interrogating her for what little direct experience she had about magic ("No Mum, tell me what you've _seen,_ not what you've guessed or read about.") then doing independent research, which had quickly proven fruitless. Any books on magic he found involved complicated rituals to bring about some minor, vague misfortune, or wishing yourself riches and happiness through "positive attraction," or some other such unfalsifiable feel-good fluff. Nothing _remotely _close to lifting a man off the ground with a couple words and the wave of a stick, let alone turning into a cat, and no mention of a "Hogwarts" anywhere.

Clearly all the _real_ magic was kept out of bookstores or libraries by some organized effort, a notion he found both troubling and thrilling. On the one hand, he was about to be part of a massive, worldwide conspiracy the likes of which he'd only read about in fiction. On the other hand, the reality of a group of people capable of secretly enforcing such a conspiracy was mildly terrifying. He wondered how omnipotent they really were, and whether non-magic authorities were involved in the coverup.

Finally, the day before yesterday another message had arrived at their house. Professor McGonagall had supplied them with a time and an address where Harry could meet her to obtain his school supplies. So this morning Harry's mum had driven him to London, uncharacteristically quiet and nervous. Harry assumed she was worried he would make a bad impression, but he was determined not to get into any trouble that might jeopardize his acceptance into the magical world. If the past few weeks had confirmed anything about his nature to himself, it was that he couldn't stand being aware of a mystery and not having the means to solve it. Just imagining going on with his life without learning more about magic... any scientific field he went into would drive him mad as he considered the true nature of reality that he'd caught a glimpse of.

Once they arrived at the appropriate address, Harry's mother parked beside a row of shops. Harry stepped out of the car and looked around, and his mother rolled down her window.

"Well," Petunia said after a pause, looking up and down the sidewalk. "I don't see Professor McGonagall... though we are a bit early. Where do you suppose the place is? 'The Leaky Cauldron,' wasn't it?"

Harry turned in a slow circle, scanning the shops along the street. Nothing _looked_ like a place that would sell magic wands, even as a joke. There was a fashionable clothing store, a hair boutique, an ice cream parlor, some fast food restaurants, a book shop (which he quickly jogged into, looked around a bit, then left), a pub - "There," he said, and pointed to The Leaky Cauldron, a quaint brick building tucked between the book shop and a record store "Maybe she's already inside."

"Hm?" Harry's mother looked vaguely in the direction he'd pointed. "Did you say you saw her?"

Harry began to point again, then stopped and looked at his Mum, then back at the pub. She was looking right at it. "What do you see between that bookshop and the record store?"

"What do you mean, dear? In the alley?"

_Alley?_ From Harry's perspective, the walls of The Leaky Cauldron were pressed up against its neighbors. "You don't see the pub right there?" he asked, pointing straight at it again.

"No," Petunia said. "You mean to tell me there is one?"

Harry felt an electric thrill go up his spine, and simply couldn't help himself. He approached a nearby couple as they walked by the car. "Excuse me, I'm afraid I brought the wrong prescription with me this morning and can't quite make out the store signs. Could you read them to me please, from right to left?" He gestured.

The man gave him a curious look, but the woman began listing names. Harry watched her eyes as she named the bookshop, then the record store, without mentioning the Leaky Cauldron. It looked as though her gaze simply passed over where it was without registering it.

"Thank you." He returned to his mother, shifting his weight from foot to foot with nervous energy as he stood beside the car and examined the pub. "It's not just you. They couldn't see it either." Here it was. Proof, however subtle, that he wasn't like other people. The now-familiar sense of disorientation came over him, and his mind raced with possibilities for how the cloaking worked. Harry wondered what would happen if he threw a rock out of the pub's window. Would the glass suddenly become visible to the people on the street? It was all he could do to not rush to the pub and begin experimenting with his mother's perception.

If wizard folk could do things like this, it was no wonder Harry couldn't find any books about them. He wondered now if a massive conspiracy was really needed to hide records of the magical world. What if non-magic folk couldn't even see the books? What else had he seen in his life without realizing no one else could? Maybe some other safety mechanism was in place, like he needed to know the name of the pub as well-

"Good morning, Mr. Potter."

Harry spun around and beheld Professor McGonagall in all her witchy glory, seeming utterly unconcerned with the odd looks she was getting from passersby.

"Good morning Professor," Harry said. "Why can't Mum see The Leaky Cauldron?"

"It's enchanted against muggle notice." The professor turned to his mother. "Good morning Mrs. Evans-Verres. I'm sorry to have kept you waiting."

"Not at all, we'd just arrived." Petunia looked back at Harry, still with that same nervousness she'd had all day. "Well, I'll be back this evening to pick you up. Be good, Harry."

She kissed him goodbye and drove away. He watched her go, then turned to Professor McGonagall. "What's a 'muggle?'"

Professor McGonagall's lips twitched. "It's good to see you again too, Mr. Potter. Muggles are what we call those without a drop of magic in them. Shall we?"

Harry followed her toward the pub. "Ok, so Dad's a muggle, but Mum too? Her sister was a witch, doesn't that mean she had some magic in her family?"

"Oh, no, if her parents were both muggles then she was a muggle too," Professor McGonagall explained in her prim, scottish voice. "What you're thinking of is what we call a 'squib.' Though children of a witch and wizard, they cannot do magic themselves, poor things, but they can perceive many magical things and use enchanted items."

Harry was trying to filter this information through his understanding of genetics, but was distracted partway as they entered The Leaky Cauldron. Harry whipped his head around to see if anything of note happened as they did, but couldn't detect any invisibility field descending on him, and no one in the street seemed to notice two people suddenly disappear.

The inside of the pub was a bit dark and shabby, with wooden tables scattered about the shadows and a grubby bar that dominated the far wall. About a dozen people were inside, most dressed in various colored robes.

"Good morning Professor McGonagall," said the barman with a smile.

"Good morning Tom."

"Is there anything I could get for - Good Lord." He peered at Harry, gaze drawn to his forehead. "Is this... can this be...?"

Harry leaned towards the bar of the Leaky Cauldron as best he could, though it came up to somewhere around the tips of his eyebrows. A question like that deserved his very best.

"Am I - could I be - maybe - you never know - if I'm not - but then the question is - who?"

"Bless my soul," whispered the old barman. "Harry Potter... what an honour."

Harry blinked, then rallied. "Well, yes, you're quite perceptive; most people don't realise that so quickly-"

"That's enough," Professor McGonagall said. Her hand tightened on Harry's shoulder and began to steer him toward the back door. "Don't pester the boy, Tom, he's new to all this."

"But it is him?" quavered an old woman sitting at the bar. "It's Harry Potter?" With a scraping sound, she got up from her chair.

"Doris -" McGonagall said warningly. The glare she gave the room was enough to stop most others from doing more than muttering amongst themselves and staring, some paused halfway out of their seats.

"I only want to shake his hand," the woman whispered. She bent low and stuck out a soft, wrinkled palm, which Harry, feeling confused and more uncomfortable than he ever had in his life, carefully shook. Tears fell from the woman's eyes onto their clasped hands. "My granson was an Auror," she whispered to him. "Died in seventy-nine. Thank you, Harry Potter. Thank heavens for you."

"You're welcome," Harry said automatically, and then shot Professor McGonagall a frightened, pleading look.

Others began to approach them again, and Professor McGonagall slammed her foot down. It made a noise that gave Harry a new referent for the phrase "Crack of Doom", and the other bar patrons once again froze in place just as the general rush was about to start.

"We're in a hurry," Professor McGonagall said in a calm voice.

They left the bar without any trouble.

"Professor?" Harry said, once they left. They were in a grassy courtyard surrounded on all sides by high brick walls. He had meant to ask what was going on, but oddly found himself asking an entirely different question instead. "Who was that pale man, by the corner? The man with the twitching eye, slumped in his seat?"

"Hm?" said Professor McGonagall, sounding a bit surprised; perhaps she hadn't expected that question either. "That was Professor Quirinus Quirrell. He'll be teaching Defence Against the Dark Arts this year at Hogwarts."

"I had the strangest feeling that I knew him..." Harry rubbed his forehead. "And that I shouldn't ought to shake his hand." Like meeting someone who had been a friend, once, before something went drastically wrong... that wasn't really it at all, but Harry couldn't find words. "And what was... all of that?"

Professor McGonagall was giving him an odd glance. "Mr. Potter... do you know... how much have you been told, about how your parents died?"

Harry returned a steady look. "My parents are alive and well, thank you. They've told me that my _genetic_ parents were killed in a car accident when I was one year old."

"An admirable loyalty," said Professor McGonagall. Her voice went low. "Though it hurts a little to hear you say it like that. Lily and James were friends of mine."

Harry looked away, suddenly ashamed. "I'm sorry," he said in a small voice. "But I have a Mum and Dad. And I know that I'd just make myself unhappy by comparing that reality to... something perfect that I built up in my imagination."

"That is quite wise of you," Professor McGonagall said quietly. "But your genetic parents died very well indeed, protecting you."

_Protecting me?_

Something strange clutched at Harry's heart. "So it... wasn't a car crash? What _did_ happen?"

Professor McGonagall sighed. Her wand tapped Harry's forehead, and his vision blurred for a moment. "Something of a disguise," she said, "so that this doesn't happen again, not until you're ready." Then her wand flicked out again, and tapped three times on a brick wall...

...which hollowed into a hole that dilated and expanded and shivered into a huge archway, revealing a pedestrian street on the other side. A long row of shops advertising everything from actual cauldrons to "dragon liver" were clearly visible, and wizards and witches bustled about from store to store, some even trailing children dressed in small, brightly colored robes.

Harry didn't blink. It wasn't like anyone was turning into a cat.

"Welcome, Mr. Potter, to Diagon Alley."

And they walked forwards, together, into the wizarding world.

Here, Harry was sure, was the true testament to the effectiveness of magical secrecy. A whole long, winding street of London City completely unknown by its inhabitants. Only powerful magic or political agreements of the highest order could keep airplanes or satellites from taking note of such a place. Here were merchants hawking Bounce Boots ("Made with real Flubber!"). There were goggles that would turn anything you looked at green, and a lineup of comfy armchairs with ejection seats for emergencies. Some of the buildings were merely a story or two high, while others had multiple floors and were oddly structured, as though relying on magic to keep them upright.

Harry's head kept rotating like it was trying to wind itself off his neck. It was like walking through the magical items section of an Advanced Dungeons and Dragons rulebook (he had no one to play the games with, but he did enjoy reading the rulebooks). Harry desperately didn't want to miss a single item for sale, in case it was one of the three you needed to complete the cycle of infinite wish spells.

Then Harry spotted something that made him, entirely without thinking, veer off from the Deputy Headmistress and start heading straight into the shop, a front of blue bricks with bronze-metal trim. He was brought back to reality only at Professor McGonagall's voice.

"Mr. Potter?" she said.

Harry blinked, then realised what he'd just done. "I'm sorry! I forgot for a moment that I was with you instead of my family." Harry gestured at the shop window, which displayed fiery letters that shone piercingly bright and yet remote, spelling out Bigbam's Brilliant Books. "When you walk past a bookshop you haven't visited before, you have to go in and look around. That's the family rule."

"That is the most Ravenclaw thing I have ever heard."

"What?"

"Nothing. Mr. Potter, our first step is to visit Gringotts, the bank of the wizarding world. Your genetic family vault is there, with the inheritance your genetic parents left you, and you'll need money for school supplies." She sighed. "And, I suppose, a certain amount of spending money for books could be excused as well. Though you might want to hold off for a time. Hogwarts has quite a large library on magical subjects. And the tower in which, I strongly suspect, you will be living, has a more broad-ranging library of its own. Any book you bought now would probably be a duplicate."

Harry nodded, and they walked on.

"Don't get me wrong, it's a great distraction," Harry said as his head kept swivelling, "probably the best distraction anyone has ever tried on me, but don't think I've forgotten about our pending discussion."

Professor McGonagall was silent for a time. "Your parents - or your mother at any rate - may have been very wise not to tell you."

"So you wish that I could continue in blissful ignorance? There is a certain flaw in that plan, Professor McGonagall."

"I suppose it would be rather pointless," the witch said tightly, "when anyone on the street could tell you the story. Very well."

And she told him of He-Who-Must-Not-Be-Named, the Dark Lord, Voldemort.

"Voldemort?" Harry whispered. It should have been funny, but it wasn't. The name burned with a cold feeling, ruthlessness, diamond clarity, a hammer of pure titanium descending upon an anvil of yielding flesh. A chill swept over Harry even as he pronounced the word, and he resolved then and there to use safer terms like You-Know-Who.

The Dark Lord had raged upon wizarding Britain like a wilding wolf, tearing and rending at the fabric of their everyday lives. Other countries had wrung their hands but hesitated to intervene, whether out of apathetic selfishness or simple fear, for whichever was first among them to oppose the Dark Lord, their peace would be the next target of his terror.

(The bystander effect, thought Harry, thinking of the Latane and Darley experiment which had shown that you were more likely to get help if you had an epileptic fit in front of one person than in front of three. Diffusion of responsibility, everyone hoping that someone else would go first.)

The Death Eaters had followed in the Dark Lord's wake and in his vanguard, carrion vultures to pick at wounds, or snakes to bite and weaken. The Death Eaters were not as terrible as the Dark Lord, but they were terrible, and they were many. And the Death Eaters wielded more than wands; there was wealth within those masked ranks, and political power, and secrets held in blackmail, to paralyse a society trying to protect itself.

An old and respected journalist, Yermy Wibble, called for increased taxes and conscription. He shouted that it was absurd for the many to cower in fear of the few. His skin, only his skin, had been found nailed to the newsroom wall that next morning, next to the skins of his wife and two daughters. Everyone wished for something more to be done, and no one dared take the lead to propose it. Whoever stood out the most became the next example.

Until the names of James and Lily Potter rose to the top of that list.

And those two might have died with their wands in their hands and not regretted their choices, for they were heroes; but they had an infant child, their son, Harry Potter.

Tears were coming into Harry's eyes. He wiped them away in anger or maybe desperation. _I didn't know those people, not really, they aren't my parents now, it would be pointless to feel so sad for them -_

When Harry was done sobbing into the witch's robes, he looked up, and felt a little bit better to see tears in Professor McGonagall's eyes as well.

"So what happened?" Harry said, voice trembling.

"The Dark Lord came to Godric's Hollow," Professor McGonagall said in a whisper. "You should have been hidden, but you were betrayed. The Dark Lord killed James, and he killed Lily, and he came in the end to you, to your cot. He cast the Killing Curse at you, and that was where it ended. The Killing Curse is formed of pure hate, and strikes directly at the soul, severing it from the body. It cannot be blocked, and whomever it strikes, they die. But you survived. You are the only person ever to survive. The Killing Curse rebounded and struck the Dark Lord, leaving only the burnt hulk of his body and a scar upon your forehead. That was the end of the terror, and we were free. That, Harry Potter, is why you are often called 'The Boy Who Lived,' and why people want to see the scar on your forehead, and shake your hand."

The storm of weeping that had washed through Harry had used up all his tears; he would not cry again.

(And somewhere in the back of his mind was a small, small note of confusion, a sense of something wrong about that story; and it should have been a part of Harry's art to notice that tiny note, but he was distracted. For it is a sad rule that whenever you are most in need of your art as a rationalist, that is when you are most likely to forget it.)

Harry detached himself from Professor McGonagall's side. "I'll - have to think about this," he said, trying to keep his voice under control. He stared at his shoes. "Um. You can go ahead and call them my parents, if you want, you don't have to say 'genetic parents' or anything. I guess there's no reason I can't have two mothers and two fathers."

There was no sound from Professor McGonagall.

And they walked together in silence, making their way through the streets of wizard, witches, and their children.


	4. Chapter 4

Chapter 4: The Efficient Market Hypothesis

* * *

"_World domination is such an ugly phrase. I prefer to call it world optimisation._"

* * *

Gringotts Bank turned out to be an imposing multistoried building made of snow-white marble. It was located partway down Diagon Alley, near an intersection with something called Knockturn Alley, and towered over the neighbouring shops. Its architecture was quite different than the "muggle" British buildings the wizarding world seemed akin to, but Harry had never studied architecture enough to pinpoint how.

He was also distracted by the pair of goblins standing at the bank's ornate double doors.

They were dressed in perfectly tailored uniforms of scarlet and gold, and discreetly examined everyone that walked by the bank. Harry knew they were goblins the way he'd have known a dragon if he saw one: they matched the description of countless fantasy novels in most metrics, if not all. Far from green skinned, the short humanoids were almost as pale as the marble behind them, but they had elongated, pointed nose and ears, extremely long, dextrous looking fingers, and slanted, piercing eyes.

Harry tried not to stare as he and Professor McGonagall approached the stairs leading up to the door. It took all his self control to keep his questions to himself however: here were living beings, apparently just as sapient as humans, but clearly from a drastically different genealogy! He wondered how closely their DNA resembled humans, and if the two species were close enough genetically to interbreed. A handful of goblin bones would probably drive Richard Dawkins into an academic frenzy, let alone sight of the real thing.

Above the great double doors was a gold and mahogany plaque bearing the symbol of an ornate key, the word "Gringotts" inscribed on it. Below that were the words _Fortius Quo Fidelius. _Harry consulted his scattered Latin; Stronger Through Loyalty?

"Good morning," he said to the goblins, who bowed in response. The doors appeared to be thick, heavy marble, but one of the goblins gripped its lower handle and swung it open with ease, though he appeared no more muscular than Harry. _Mental note: size does not correlate with strength in the magical world._

Harry and Professor McGonagall walked through the door side by side, and the goblin behind them closed the door. They were in a small entrance hall that was mostly empty, though curiously there were a pair of fireplaces to either side. In front of them was another set of doors, these silver, also flanked with goblins. As Harry approached, he saw writing engraved on it:

_Enter, stranger, but take heed_  
_Of what awaits the sin of greed_  
_For those who take, but do not earn,_  
_Must pay most dearly in their turn._  
_So if you seek beneath our floors_  
_A treasure that was never yours,_  
_Thief, you have been warned, beware_  
_Of finding more than treasure there._

Harry swallowed. It should have seemed silly, something out of a nursery tale... but standing in what seemed literally a goblin stronghold, the words conveyed a quiet, self-assured threat that sent a shiver up Harry's spine. _Further note__: do not get on a goblin's bad side._

"Greetings Madame McGonagall," said the goblin to their right, voice reedy and accented with a dialect Harry had never heard before. "Greetings Master Potter."

"Greetings," Harry said, and glanced at Professor McGonagall curiously.

"I informed the bank that we would be arriving today, so they would have your family vault key readily located," she explained. "It hasn't been accessed in a decade."

"Ah. Well, thank you for keeping my inheritance safe for me," Harry told the goblin. He felt rather awkward claiming money from parents he had never met, but knew he would need it for school supplies that were sure to be very expensive. How much would a genuine magic item go for in the muggle world? People already payed exorbitant prices on claptrap that didn't even work; the potion for perfect teeth he'd seen in a shop window would probably sell for hundreds of pounds, maybe thousands. He hoped he would be able to afford his wand and books at least.

"Merely our duty, Master Potter," the goblin said, and bowed again. Was it Harry's imagination, or was there a slightly mocking tone to the goblin's words?

The goblin opened the door, revealing a long hall filled with goblins and wizards. The latter mostly stood in queues, while the former walked about with an air of urgent business or stood behind podiums and desks that placed them a head above their clients. A rather obvious bit of over-compensation, but Harry didn't blame them in the slightest.

All this Harry saw through what appeared to be a thin film of water, falling gently from somewhere above the other side of the doors and trickling into a narrow grate on the floor.

"It's called the Thief's Downfall," Professor McGonagall said, seeing Harry's hesitation. "It washes away many forms of magical disguise, and will ensure we are who we appear to be. Your scar will become visible after we pass through, but I'll obscure it again when we leave." The witch walked through the water, then turned to wait for him.

Harry took a breath and stepped through, eyes shut and shoulders tight as he anticipated a cold bath. The water was lukewarm however, and quickly evaporated. Within seconds he felt completely dry, and he opened his eyes in astonishment, hands running through his hair.

Professor McGonagall gave him a brief smile, then led the way to a podium labeled "Special Appointments." Harry followed, trying not to stare at any one thing too long. He saw a witch weighing a jingling pouch in her hand, goblins writing on long sheets of parchment with feathered quills, and a wizard handing an emerald the size of Harry's fist to his goblin teller, who took out a monocle and examined the gem.

The goblin they approached seemed older than the others, head mostly bald and hair long and white, with small spectacles perched on his long nose. "Yes?" he asked without glancing up from the parchment he was examining.

"Harry Potter is here to access his vault."

There was a slight pause, and the goblin's eyes flicked upward at Harry. "You have the key?"

Professor McGonagall pulled an iron key out of her sleeve, the letter P engraved at its handle. She held it over the desk.

The older goblin took the key, squinting at it for a moment and running his thin fingers over the engraving before handing it back. "Very good." The goblin reached to the side and picked up a bell, which he rang in a deliberate pattern: _ding-a-dong, ding-ding, dong-ding! _"Griphook will guide you." He rolled his parchment up a bit and continued reading. Harry saw that it extended all the way down to the floor. He wondered why a society that clearly had access to books would still use scrolls. Perhaps it was a goblin thing, along with their aversion to fountain pens.

Griphook proved to be a youngish goblin, with relatively smooth skin and full dark hair slicked back over his head. He bowed after approaching them. "Madame McGonagall. Master Potter. Follow me, please."

The goblin led them out of the main hall through a side door, which opened into a downward staircase. The stairs were clean white marble at first, but soon changed to dark stone, and the glowing chandeliers gave way to flaming torches. Harry knew they must have been enchanted, as there was no smoke, which would have filled the tunnel without some airway to escape through.

_I'm walking down a goblin tunnel,_ Harry thought with a renewed touch of unreality. It soon leveled off, and then the walls fell away to reveal long, twisting paths with rail tracks along the floor. Mine carts sat on short tracks that branched off the main lines, and Griphook led them to one.

"Please step aboard, Master Potter."

Harry met the goblin's gaze. "Mister will suffice, thank you." Harry remembered vacationing with his parents at an expensive hotel once. They'd been waited on by the staff with an overwhelming deference that was enjoyable, but in an occasionally uncomfortable way. Though the thought of having servants (or better yet, minions) was appealing on a number of levels, he didn't quite feel comfortable being called "master" by another race. Especially not coupled with the vaguely mocking tone he sensed from the goblins, though perhaps that was merely a difference in mannerisms or accent that didn't quite translate well. "And my full name is Potter-Evans-Verres."

The goblin peered back at him for a silent moment, then another. Harry didn't drop his gaze, and the goblin finally inclined his head briefly. "As you say, Mr. Potter-Evans-Verres."

Harry followed Professor McGonagall onto the trolley, ignoring her speculative look. He noted the lack of hand rails or seat belts, and began to feel nervous as Griphook stepped in and closed the side hatch. "Is this really the safest way to conduct a banking transaction?"

"No," Griphook said with a wide grin, revealing sharp teeth. He pulled a key out of his vest pocket, identical to the one Professor McGonagall had, and inserted it into a keyhole at the back of the trolley. "But then, it wouldn't be much good if it was." He twisted the key, and the mine cart shuddered, rolled slowly onto the main track, then _zoomed _forward at roughly one hundredth the speed of sound.

Harry's yell of surprise was soon lost behind them as the wind whipped it from his lips, and he gripped the sides of the cart until his knuckles turned white. He gave Professor McGonagall an accusatory glare, and the witch merely raised an eyebrow, arms crossed nonchalantly over her chest as her lips twitched at the corners. Harry grit his teeth and slowly drew his hands back to his sides, ignoring the lurching sensations in his stomach as the cart rocketed through the twisting caverns, down, down, down.

_Of course, they'd assure it's safe if you have the proper means to travel it,_ Harry chides himself. Once he got over the initial shock, Harry found the cart ride rather enjoyable, in a roller-coaster sort of way. They passed by glittering crystal outgrowths, various sized vault doors, and through another Thief's Downfall, this one much bigger and ice cold, though he once again dried in seconds.

Harry raised his voice over the clatter of the wheels. "Do all wizards keep their money here?"

"All that care about their gold!" Griphook replied.

"Gold?"

"And silver, and bronze!" Professor McGonagall called out. "The gold coins are called Galleons, the silver Sickles, and the bronze Knuts. It's twenty-nine Knuts to a Sickle, seventeen Sickles to a Galleon!"

Harry was still processing the implications of this as they shot around a particularly wide corner, and his next question was interrupted by a burst of fire that illuminated the darkness around them. Harry twisted his head around, but the chamber was already out of sight. "What was that?" he yelled back at Griphook.

"Just a dragon!" Griphook said with a smirk, and Harry couldn't tell if he was joking or not. His mind raced in a whole new direction, monetary matters temporarily tabled.

Soon after, the cart began to slow, its deafening rattle quieting little by little until it finally took one of the branching paths. The trolly coasted along it and reached a relatively small vault door with no markings on it. Griphook hopped out of the cart and walked up to the door, then inserted the same key he'd put into the trolley cart. A second keyhole was parallel to it, and Professor McGonagall inserted her, or rather Harry's, key into that one. They twisted together, there was a heavy metal _clunk_, and the door swung inward.

Harry stepped inside the brightly lit marble room and felt his jaw unhinge in a gape.

Heaps of gold Galleons. Stacks of silver Sickles. Piles of bronze Knuts. More money than he'd ever seen in one place, all in the form of gleaming treasure that would make Bluebeard jealous. _This... is all mine?_

Harry was vaguely aware of Professor McGonagall leaning casually against the wall, eyes intent. Watching him. Well, that made sense. Being plopped in front of a giant heap of gold coins was a test of character so pure it was archetypal.

Harry closed his mouth. First things first... get an estimate of how much money he was actually looking at, in a way he could understand. "Are these coins the pure metal?" he asked Griphook.

"What?" the goblin spat from the doorway, voice harsh. "Are you questioning the integrity of Gringotts, Mr. Potter-Evans-Verres?"

"No," said Harry, "not at all, sorry if that came out wrong, sir. I just have no idea at all how your financial system works. I'm asking if Galleons in general are made of pure gold."

"Of course," said Griphook.

"And can anyone coin them, or are they issued by a monopoly that collects seigniorage?"

"What?" said Professor McGonagall.

Griphook grinned. "Only a fool would trust any but goblin coin!"

"In other words," Harry said, "the coins aren't supposed to be worth any more than the metal making them up?"

Griphook stared at Harry. Professor McGonagall looked confused.

"I mean, suppose I came in here with a ton of silver. Could I get a ton of Sickles made from it?"

"For a fee, Mr. Potter-Evans-Verres." The goblin watched him with glittering eyes. "For a certain fee. Where would you find a ton of silver, I wonder?"

"I was speaking hypothetically," Harry said. _For now, at any rate._ "So... how much would you charge in fees, as a fraction of the whole weight?"

Griphook's eyes were intent. "I would have to consult my superiors..."

"Give me a wild guess. I won't hold Gringotts to it."

"A twentieth part of the metal would well pay for the coining."

Harry nodded. "Thank you very much, Mr. Griphook."

_So not only is the wizarding economy almost completely decoupled from the Muggle economy, no one here has ever heard of arbitrage._ The larger Muggle economy had a fluctuating trading range of gold to silver, so every time the Muggle gold-to-silver ratio got more than 5% away from the weight of seventeen Sickles to one Galleon, either gold or silver should have drained from the wizarding economy until it became impossible to maintain the exchange rate. Bring in a ton of silver, change to Sickles (and pay 5%), change the Sickles for Galleons, take the gold to the Muggle world, exchange it for more silver than you started with, and repeat.

Wasn't the Muggle gold to silver ratio somewhere around fifty to one? Harry didn't think it was seventeen, anyway. And it looked like the silver coins were actually _smaller_ than the gold coins.

Then again, Harry was standing in a bank that _literally_ stored your money in vaults full of gold coins guarded by dragons, where you had to go in and take coins out of your vault whenever you wanted to spend money. The finer points of arbitraging away market inefficiencies might well be lost on them. He'd be tempted to make snide remarks about the crudity of their financial system...

_But the sad thing is, their way __might actually be__ better._

On the other hand, one competent hedge fundie could probably own the whole wizarding world within a week. Harry filed away this notion in case he ever ran out of money, or had a week free.

Meanwhile, the giant heaps of gold coins within the Potter vault ought to suit his near-term requirements.

Harry stepped forward, and began picking up gold coins with one hand and dumping them into the other.

When he had reached twenty, Professor McGonagall coughed. "I think that will be more than enough to pay for your school supplies, Mr. Potter."

"Hm?" Harry said, his mind elsewhere. "Hold on, I'm doing a Fermi calculation."

"A _what?_ " said Professor McGonagall, sounding somewhat alarmed.

"It's a mathematical thing. Named after Enrico Fermi. A way of getting rough numbers quickly in your head..."

Twenty gold Galleons weighed a tenth of a kilogram, maybe? And gold was, what, ten thousand British pounds a kilogram? So a Galleon would be worth about fifty pounds... The mounds of gold coins looked to be about sixty coins high and twenty coins wide in either dimension of the base, and a mound was pyramidal, so it would be around one-third of the cube. Eight thousand Galleons per mound, roughly, and there were around five mounds of that size, so forty thousand Galleons or 2 million pounds sterling.

Not bad. Harry smiled with a certain grim satisfaction. It was too bad that he was right in the middle of discovering the amazing new world of magic, and couldn't take time out to explore the amazing new world of being rich, which a quick Fermi estimate said was roughly a billion times less interesting.

_Still, that's the last time I ever mow a lawn for one lousy pound._

Harry wheeled from the giant heap of money. "Pardon me for asking, Professor McGonagall, but I understand that my parents were in their twenties when they died. Is this a _usual_ amount of money for a young couple to have in their vault, in the wizarding world?" If it was, a cup of tea probably cost five thousand pounds. Rule one of economics: you can't eat money.

Professor McGonagall shook her head. "Your father was the last heir of an old family, Mr. Potter. It's also possible..." The witch hesitated. "Some of this money may be from bounties placed on You-Know-Who, payable to his ki- ah, to whoever might defeat him. Or those bounties might not have been collected yet. I am not sure."

"Interesting..." Harry said slowly. "So some of this really is, in a sense, mine. That is, earned by me. Sort of. Possibly. Even if I don't remember the occasion." Harry's fingers tapped against his trouser-leg. "That makes me feel less guilty about spending _a very tiny fraction of it! Don't panic, Professor McGonagall!_ "

"Mr. Potter! You are a minor, and as such, you will only be allowed to make _reasonable_ withdrawals from -"

"I am _all about_ reasonable! I am totally on board with fiscal prudence and impulse control! But I _did_ see some things on the way here which would constitute _sensible, grown-up_ purchases..."

Harry locked gazes with Professor McGonagall, engaging in a silent staring contest.

"Like what?" Professor McGonagall said finally.

"Trunks whose insides hold more than their outsides?"

Professor McGonagall's face grew stern. "Those are _very_ expensive, Mr. Potter!"

"Yes, but -" Harry pleaded. "I'm sure that when I'm an adult I'll want one. And I _can_ afford one. Logically, it would make just as much sense to buy it now instead of later, and get the use of it right away. It's the same money either way, right? I mean, I _would_ want a good one, with _lots_ of room inside, good enough that I wouldn't have to just get a better one later..." Harry trailed off hopefully.

Professor McGonagall's gaze didn't waver. "And just what would you _keep_ in a trunk like that, Mr. Potter -"

"Books."

"Of course," sighed Professor McGonagall.

"You should have told me _much earlier_ that sort of magic item existed! And that I could afford one! Now my father and I are going to have to spend the next two days _frantically_ hitting up all the secondhand bookshops for old textbooks, so I can have a decent science library with me at Hogwarts - and maybe a small science fiction collection, if I can assemble something decent out of the bargain bins. Or better yet, I'll make the deal a little sweeter for you, okay? Just let me buy -"

"_Mr. Potter!_ You think you can _bribe_ me?"

"What? _No!_ Not like that! I'm saying, Hogwarts can keep some of the books I bring, if you think that any of them would make good additions to the library. I'm going to be getting them cheap, and _I_ just want to have them around somewhere or other. It's okay to bribe people with _books,_ right? That's a -"

"Family tradition."

"Yes, exactly."

Professor McGonagall's body seemed to slump, the shoulders lowering within her black robes. "I cannot deny the sense of your words, though I much wish I could. I will allow you to withdraw an additional hundred Galleons, Mr. Potter." She sighed again. "I _know_ that I shall regret this, and I am doing it anyway."

"That's the spirit! And does a 'mokeskin pouch' do what I think it does?"

"It can't do as much as a trunk," the witch said with visible reluctance, "but... a mokeskin pouch with a Retrieval Charm and Undetectable Extension Charm can hold a number of items until they are called forth by the one who emplaced them -"

"Yes!" Harry's excitement made him shift from foot to foot, eyes alight. "I definitely need one of those too! Batman's utility belt of holding! Never mind my swiss army knife, I could carry a whole tool set in there! Or _books!_ I could have the top three books I was reading on me at all times, and just pull one out anywhere! I'll never have to waste another minute of my life! What do you say, Professor McGonagall? It's for the sake of children's reading, the best of all possible causes!"

"...I suppose you may add another ten Galleons."

Griphook was favouring Harry with a gaze of growing respect, possibly even outright admiration.

"And a little spending money, like you mentioned earlier. I think I can remember seeing one or two other things I might want to store in that pouch."

"_Don't push it, Mr. Potter._"

"But oh, Professor McGonagall, why rain on my parade? Surely this is a _happy_ day, when I discover all things wizarding for the first time! Why act the part of the grumpy grownup when instead you could smile and remember your own innocent childhood, watching the look of delight upon my young face as I buy a few toys using an insignificant fraction of the wealth that I earned by defeating the most terrible wizard Britain has ever known, not that I'm accusing you of being ungrateful or anything, but still, what are a few toys compared to that?"

"_You,_" growled Professor McGonagall. There was a look on her face so fearsome and terrible that Harry squeaked and stepped back, knocking over a pile of gold coins with a great jingling noise and sprawling backwards into a heap of money. Griphook sighed and put a palm over his face. "I would be doing a great service to wizarding Britain, Mr. Potter, if I locked you in this vault and left you here."

And they left without any more trouble.

* * *

_Hey everyone. This has been a lot of fun, and the feedback has been very gratifying. I'm probably going to stop here: chapter 5 is where I felt the quality began to reflect the rest of the story, and I'd have little to add to it. I might revisit this to provide more context for certain later events (Harry shopping for his wand, for example), but in the meantime I think these chapters do the job of smoothing out the introduction of Harry Potter and the Methods of Rationality. If you somehow found yourself here while being unaware of that fanfic and want to read more, you can continue the story at s/5782108/5/Harry-Potter-and-the-Methods-of-Ration ality/, or just by googling HPMOR.  
_


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